1. Field of the Invention
The present invention relates to an optical module.
2. Description of the Related Art
An optical sub-assembly (OSA) that converts an electric signal to an optical signal and vice versa is mounted in a transmitter-receiver device (also referred to as a transceiver) for optical fiber transmission. It is known to use a flexible wiring board for electrically connecting the optical sub-assembly with a main substrate or the like. JP 2012-047823 A discloses the structure in which the flexible wiring board is connected to the optical sub-assembly as described above.
The optical sub-assembly includes a plurality of connection electrodes including lead pins and a circuit pattern of a feedthrough. The plurality of connection electrodes are arranged on a line in many cases. Wires formed on the flexible wiring board include a plurality of connection terminals including pads and through holes. The connection electrodes of the optical sub-assembly and the connection terminals of the flexible wiring board are bonded together with solder, whereby a plurality of solder bonding portions are formed. When the plurality of connection electrodes are arranged on a line, the plurality of solder bonding portions are also arranged on a line. Therefore, when the flexible wiring board is bent, the wire is easily bent at a position adjacent to the solder bonding portion which is hard, and thus stress is concentrated. In order to prevent disconnection, it is desired to avoid the concentration of stress described above.